Had a discussion with Nerd-Vol in a thread last night/this morning, and I pulled out of my ass something that I think is actually a pretty decent idea to control costs in F1 without stifling innovation with overly restrictive formulae. Unfortunately, it only pertains to engines as it sits.
The idea, simply, is to provide a price point at which engine suppliers can sell engines to teams. Anything goes as far as engine technology is concerned (perhaps some very vague regulations concerning displacement, etc., but nothing serious), but the limiting factor is that engine suppliers can only get X amount of dollars for each engine sold. Controls costs for teams, keeps development steady but not overwhelming, and would provide for potentially interesting and differing ideas.
Obviously the engine supplier/team relationships would have to be very closely monitored (particularly financially), but I think it could offer up for a far more interesting set of engines on the grid than exists under the current set-up, and one that doesn't break the bank.
Have no clue how to apply this kind of thinking to the rest of the costs in the series, though.